Australia: The Significance of Sea-Level Histories - Assignment Example

Australia: The Significance of Sea-Level Histories in Coastal Zone Management Introduction: The earth's crust is the region where the solid and liquid elements interface with the gaseous one and it is of special significance because it is the region where all manners of life-forms thrive. Since the industrial revolution, when humankind got a fillip in acquiring machines for doing work which previously they themselves did, human consumption has reached such levels that sustainability in terms of the environment - the interface between the crust and the atmosphere - has become endangered. As such humans have, perforce, awaken to the fact that the very existence of life on earth is under threat as the environment they live in is under threat from the depredations of excessive consumption that does not consider sustainability of habitats. Responsible individuals and governments almost everywhere on Earth have started measures that can fast ensure equitable consumption with environmental conservation. In terms of conservation measures it is noted that the Earth's crust has varied terrain and topography that each require exclusively special techniques for sustainable consumption. The paper specifically inquires into one such terrain - coastal zones - in one specific country - Australia. It is not only present consumption levels that must be sustainable but also future ones that accrue through present and future development. Coastal Zone Management: The coastal zone, anywhere, is a combination of different types of terrain and topographies and techniques used to conserve it under separate forms of human exploitation are all housed under one countrywise policy - integrated coastal zone management (ICZM). In the context of the paper ICZM shall be reviewed in the context of sea-level histories in special relevance to the Commonwealth of Australia. "Everybody wants access to the coast. The.coast is where people want to live, do business, create development and where people want to recreate (Holliday, 1998) (Derived: Ed. Lazarow et al, 2006). This simple quote puts in a nutshell the types of human exploitation that coastal zones may be subjected to. Australia has a coastal zone that extends almost 36,000 km, excluding external territories, and is considered one of that country's greatest assets (National Cooperative Approach, Australia, 2006). The 'National Cooperative Approach to Integrated Coastal Zone Management, Framework and Implementation Plan' is a report produced under the 'Natural Resource Management Ministerial Council', Commonwealth of Australia. The wide biodiversity thriving within this extensive zone exists in an interaction among the interesting mix of terrestrial, marine and estuarine ecosystems that are generated by the wide-ranging array of climatic, geographical and oceanographic variants (National Cooperative Approach, Australia, 2006). The variants within the habitats and life-forms require as wide a range of conservation measures and these measures are further complicated by the wide-ranging varieties of human activities this broad band of Australian territory attracts. Taking into consideration this wide range of factors that have to be assimilated in conjunction to enable positive conservation under projected levels of future consumption, partly derived from development, a result-oriented ICZM plan for the extensive Australian coastal zone is highly complex. This is borne out by the fact that the 'State of the Environment Report (2001)' that notes that, despite efforts at efficient CZM (coastal zone management), zonal quality, as per diverse predetermined criteria, continued to deteriorate and the rate of consumption of coastal resources continued to increase at a rate that would be unable to provide sufficient time for already jeopardized resources to recover (National Cooperative Approach, Australia, 2006). This last noted fact emphasizes the importance of this paper that strives to ascertain how sea-level histories can assist in ICZM. This is how the next part of the paper is built up - assessing how sea-level histories can prove helpful to efficient ICZM, particularly in the Australian context. Sea-Level Histories: It is necessary at this point to acknowledge that, to conserve coastal zones, it is first necessary to assess how vulnerable they are to various influences, including natural ones. It is necessary to understand how coastal processes, local and otherwise, may influence coastal erosion, flooding and sea-level changes to understand in part how the interrelated factors - present conservation status, present consumption and development in a particular region - may affect the future conservation status of that particular region (Harvey, 2002). In the present context, it is not only necessary to assess coastal vulnerability to these coastal processes that are primarily localized but it is significantly necessary to assess vulnerability of localized coastal regions to global phenomena like global warming. Susceptibility of a signified coastal region to sea-level changes wrought by global warming can be more accurately assessed if past sea-level histories can be accessed to understand that coastal region's innate vulnerability to various coastal processes, natural or otherwise and localized or global (Harvey, 2002). Harvey, 2002, notes that a recent (2001) Intergovernmental Panel on Climate Change, upon suitable scientific advice, predicted an overall sea-level rise of 0.09-0.88m , with median figures at 0.48m, and the implication of this predicted rise for Australian coastal regions varied. Harvey, 2002, notes that this global prediction has diverse implications for Australian coastal management as the diverse coastal regions would be prone to as diverse coastal process factors that, in land/sea interaction, would induce sea-level changes that were exclusively local in effect. Harvey, 2002, thus advised that, to predict future sea-level changes induced by global climatic phenomena like global warming, especially in the Australian context, it would first be necessary to understand case studies of historic sea-level changes on a localized basis. This is so because coastal regions in Australia are diverse with diverse climatic, geographic and oceanographic characteristics that require separate assessment techniques on a localized basis to account for their diversity. Coastal Protection Policies: The 'Coastal Protection Board', South Australia, as per Harvey, 2002, used a 100-year average return interval (ARI) water level as a standard for development in South Australian coastal regions. It is notable that other conservation measures, such as controlling human activities that are detrimental to environment, are necessary to protect habitats, both human and otherwise, but protection from coastal processes like erosion, flooding and sea-level rise both from global and local phenomena is also necessary to protect these habitats, both existing and developing. While historic ARI can be utilized to protect such habitats, human and otherwise, existing and developing, from future predictable sea-level rise historic records, 100 years for minor development and 200 for major ones, of erosion are used for protection against localized erosive and sedimentation processes that tend not only to generate sea-level changes but also other localized phenomena that tend to threaten habitats (Harvey, 2002). Such protection measures as these two - sea-level changes due to flooding, erosion and sedimentation, including storm erosion, require past records of these coastal phenomena. Sea-Level Changes: Sea-level changes can be either short-term or long-term. Short-term changes can be due to tidal effects, which are generally dependent upon seasonal variations caused by the Earth's revolution/rotation motions in interaction with the motive forces of other heavenly bodies, especially the sun and the moon. The Earth's positional variants as it rotates and revolves in relation to the sun and the moon also affect insolation levels that, in the long and short terms, affect sea-levels in turn. Its three positional variants are - orbital eccentricity, precession and its axial tilt to its orbital plane. These affect both short and long term changes in sea-levels but, unfortunately, a more extensive discussion on this is not possible here for the sake of conserving brevity. Short-term changes may also be influenced by seasonal drainage changes in freshwater induction from rivers and other bodies. These change seasonally due to precipitation patterns in the immediate region and/or other influential regions. Short-term changes can also be affected by tectonic activity that may change regionally topography drastically. Short-term changes are also wrought by regional weather phenomena like wind patterns (storms or calms) and wave patterns. Even large storm or other weather systems in adjacent regions can affect sea-levels in the short term. Long-term sea-level changes are more complex. Glaciation and intermediate periods can increase or decrease sea levels. Even slow events like continental drifts can affect sea levels ultimately. Climate changes affected over lengths of time can ultimately also affect sea levels in the long term. Broadly and technically, sea level changes can be affected in two ways. The steric effect - Changes in global climate can affect thermal and salinity-density equilibrium of sea water (SESWG, 2008) and change sea-levels. Mass budget changes - changes in equilibrium of water exchange systems from polar ice sheets and mountain glaciers, atmospheric water vapor and land hydrological variations and human effects like water reservation in artificial reservoirs and groundwater extraction. All these must be superimposed on the Earth's internal and external motions and relative position where internal motions may be construed as those affecting its lithosphere ((SESWG, 2008). These broad level changes can affect both global and local sea levels. It also must be noted that these change patterns are highly complex and each require extensive review for complete understanding, a review process that, at present, is beyond the scope of this paper. The 'National Tidal Facility', located in Adelaide, does sea level monitoring and analysis for the purposes of assessing changes in sea levels and making tidal predictions for Australian coastal regions. Time series data on historic trends in sea levels in the region is available from here. It is notable that this paper does not specifically detail rates of changes in sea levels in Australian coastal regions. This is so because these rates are highly variable regionwise and are dependent upon various factors, mentioned earlier in the paper, which each assessable region is prone to. Even topological features such as transgression and regression processes have been eschewed for more general information that is more comprehensive of the interacting relationship between sea level changes and life form survival on Earth. Conclusion: Sea level changes can be historically assessed from data available at tidal gauge sites near the coast while more ancient data can be available from sedimentation patterns - carbon isotope signatures and fossilized remains as well as sedimentation types and levels. A recent feature on the 'BBC' channel highlighted the fact that the Adelaide region has been historically prone to high intensity storms that drastically induce surges that may, in turn, actually destroy large parts of the city built on low land. Evidence of the high intensity storms, which have not struck the city in recent years but may in the near future, was cleverly derived by the scientists from coral remains found upshore of the region. This demonstrates that not only sea level data derived in the recent past but also data derivable from ancient sedimentation processes prove useful in predicting modern phenomena such as likelihood of large storm systems in a particular vicinity. Thus, efficient Coastal Zone Management requires not only recent historic sea level change data but also historic data that are several hundred or even several million years old. The paper concludes that, generally, it has presented a very comprehensive view of sea level changes and the usefulness in studying these changes in the perspective of coastal zone management. References: Harvey, Nick, Sea-Level Change and Coastal Stability in South Australia, Coast to Coast, 2002, p. 149-152. What are the Interactions among Ice Masses, and the Solid Earth, and their Implications for Sea-Level Changes, Solid Earth Science Working Group, Jet Propulsion Laboratory, California Institute of Technology, 2008. Extracted on 3rd January, 2008, from: http://solidearth.jpl.nasa.gov/PAGES/sea01.html National Tidal Centre, Australian Government, Bureau of Meteorology, 2008. Extracted on 4th January, 2008, from: http://www.bom.gov.au/oceanography/projects/ntc/ntc.shtml Ed. Lazarow, Neil, et al, Coastal management in Australia, Key institutional and governance issues for coastal natural resource management and planning, October 2006. Extracted on 4th January, 2008, from: http://www.coastal.crc.org.au/pdf/Coastal_Management_in_Australia.pdf National Cooperative Approach to Integrated Coastal Management: Framework and Implementation Plan, National Resource Management Ministerial Council, Commonwealth of Australia, 2006. Extracted on 4th January, 2008, from: http://www.environment.gov.au/coasts/publications/framework/index.html Bibliography: Walsh, Kevin, et al, Sea Level Rise Projections and Planning in Australia, Coast to Coast, 2002, p. 1-4. N P. Stephens and Dawn Y. Sumner, "Late devonian carbon isotope stratigraphy and sea level fluctuations, Canning Basin, Western Australia" (2003). Palaeogeography Palaeoclimatology Palaeoecology. 191 (2), pp. 203-219. Postprint available free at: http://repositories.cdlib.org/postprints/464 Sloss, Craig R., et al, Holocene sea-level change on the southeast coast of Australia: a review, The Holocene, Vol. 17, No.7, 999-1014; 2007. Read More